Sintering is a process of forming objects from metallic powder by applying heat to the powder. In one known example, sintering involves heating metal powder to a temperature that is below the melting point of the metal powder. Although the metal powder does not melt during this process, a coherent bonded mass may be formed. Some known examples of sintering are the manufacture of ceramic objects, the manufacture of bearings and the process of powder metallurgy.
Sintered bronze for example, is a porous material manufactured by heating metal bronze powder below its melting point until the particles adhere to each other. Sintered bronze may be used as a filter. The advantages of using sintered bronze as a filtering material include its ability to regenerate the filter element as well as its ability to filter small particles with high precision. Sintered bronze also has superior performance when filtering highly flammable gases such as oxygen, and is therefore desirable as a filter material in applications such as diving systems or other compressed oxygen systems.
Some of the existing sintered filters that are used in scuba diving apparatuses are manufactured in tubes. Consequently, these sintered bronze filters generally have two to three times less surface area than conventional pleated wire mesh designs. This leads to a number of disadvantages in using sintered bronze tube filters as opposed to pleated wire mesh filters, such as a low dirt holding capacity and a high pressure drop across the filter element.